UK laws state that the simple possession of indecent photographs of children is an offence and any distribution of such material can warrant a longer prison sentence.

Zero tolerance

Jimmy Nguyen, founder of crypto-cash company nChain, which oversees the BSV currency, said it had "zero tolerance" for illegal use of the system.

"The Bitcoin SV blockchain is not a place for criminal activity - and if you use it for illegal purposes, you will leave a digitally signed evidence trail that cannot be erased," he told BBC News.

"We stand ready to work with global law enforcement authorities to stamp out this and any other illegal misuse of Bitcoin."

Ryan Charles, founder of Money Button, said: "Since most businesses increased the size of allowed data recently, making it possible to post large files, criminals are trying to push the limits."

Easily accessible

The abuse images embedded in the BSV blockchain were spotted when they appeared on Bitcoinfiles.org.

The website lets people browse a rolling list of messages and other content added to the blockchain.

The appearance of the images prompted police to investigate. Bitcoinfiles.org has since closed the blockchain browsing service.

In addition, Money Button has banned the user that uploaded the material.

It has also put in place filtering systems to spot when anyone tries to upload similar content. Money Button is part-funded by nChain.

"Criminals should understand that everything on the blockchain is signed, time-stamped, and linked to everything else," said Mr Charles.

"We have all the information we need to track down criminals and prosecute them."

Information about the person who uploaded the images has been passed to the authorities.

'Not yet mature'

Eric Erstu, who runs the Cryptograffiti website that lets people read messages embedded in the Bitcoin blockchain, said: "There is nothing that could have prevented this from happening in other blockchains.

"It takes special care to seek and find illegal content from any block chain, as it is not a trivial process," he told BBC News.

"As for law enforcement, they would have to do the good old detective work in hope of tracking down the person who uploaded the illegal content on the block chain.

"Since everything you do on the blockchain is immutable, tracking down criminals is not too difficult."